The invention relates to a system to generate power from a low level heat source. A steadily increasing demand for energy has placed considerable pressure on our gas, oil, and coal supplies, as well as creating a number of environmental problems. Alternate energy sources, such as nuclear, solar, hydroelectric and geothermal, are being pressed into service.
A second approach involves energy conservation. Total energy demand has been reduced by increasing the efficiency of motor vehicles, home appliances lighting and the heating of homes and commercial buildings.
A third approach involves energy recovery A significant portion of energy in electrical power generation, industrial processes, and comfort heating and cooling is lost to the atmosphere as waste heat. This follows from the laws of thermodynamics which state that efficiency increases with the temperature of the working medium, and in conventional design, it is not economically feasible to use heat below a predetermined temperature level.
A fourth approach involves building a reliable power generation station with zero, or near zero, emissions. A problem in today's society involves the extensive use of energy changing machines that emit massive amounts of pollution in our air, streams, and ground. Therefore, creating reliable, almost inexhaustible, low grade heat generating plants with zero emissions, or near zero emissions, will greatly assist in halting this pollution.
Much research and development is presently taking place to partially recover the vast amount of energy which is now being wasted as low grade heat. The present invention is directed to such a heat recovery system.
A number of patents have been issued dealing with this problem. U.S. Pat. No. 3,888,084, issued on Jun. 10, 1975, to Gilbert Hawkins, shows a system to recover waste heat from an automobile engine. Coolant water is heated in the water jacket of the engine and flows in heat exchange relationship with a closed Freon system. The heated Freon is raised in pressure to drive a motor which returns work to the engine.
U.S. Pat. No. 4,006,595, issued on Feb. 8, 1977, to William J. Forbes, shows a heat source for superheating Freon to drive a turbine. A pair of pressurized storage tanks are used alternately as a source and sink for the Freon.
U.S. Pat. No. 4,177,651, issued on Dec. 11, 1979, to Lorrell C. McFarland, shows a Freon driven engine powered by a heat source derived from solar energy. The Freon engine drives a conventional air conditioning compressor.
While the above mentioned patents do teach some energy recovery systems, the prior art does not teach a system having the flexibility of application and the overall efficiency of the disclosed invention.